2105-94-4Relevant articles and documents
Influence of the type of halogen substituent on in vivo and in vitro phase II metabolism of 2-fluoro-4-halophenol metabolites formed from 3-halo-fluorobenzenes
Soffers,Veeger,Rietjens
, p. 759 - 774 (1994)
The influence of a change in the type of halogen substituent on phase II metabolism of 2-fluoro-4-halophenol metabolites formed from 3-halo-fluorobenzenes was studied in vivo and in vitro using 19F nmr and spectroscopic assays. The ratio of sulphation to glucuronidation of 2-fluoro-4-halophenol metabolites formed from 3-halofluorobenzenes decreased from 48 to 13 to 6 when the halogen substituent varied from fluorine to chlorine to bromine. When the 2-fluoro-4-halophenols themselves were administered to the rats, the ratio of sulphation to glucuronidation was not affected by the type of halogen substituent at C4 and at a constant value of 0.6, i.e. significantly lower. Kinetic data for P450 catalysed hydroxylation of the 3-halo-fluorobenzenes and for sulphation and glucuronidation of their 2-fluoro-4-halophenol metabolites were obtained from in vitro microsomal and cytosolic incubations. These data demonstrate that the effects of varying the halogen substituent on phase II metabolism of the 2-fluoro-4-halophenol metabolites can be mainly ascribed to an apparently decreased K(m) for the glucuronidation of the 2-fluoro-4-halophenols with a change in the halo substituent from fluorine to chlorine to bromine. Results from calculations on electronic and structural characteristics of the three 4-halo-2-fluorophenols demonstrate that the best explanation for the decrease in the apparent K(m) of the glucuronidation from 2,4-difluoro- to 4-chloro-2-fluoro- to 4-bromo-2-fluorophenol might be an increase in the hydrophobicity of the phenol. An increase in the hydrophobicity of the phenol would provide an increased possibility for substrate accumulation in the hydrophobic membrane environment of the UDP-glucuronyltransferases, resulting in an apparently decreased K(m).
Regioselective monobromination of phenols with KBr and ZnAl–BrO3?–layered double hydroxides
Wang, Ligeng,Feng, Chun,Zhang, Yan,Hu, Jun
supporting information, (2020/02/22)
The regioselective mono-bromination of phenols has been successfully developed with KBr and ZnAl–BrO3?–layered double hydroxides (abbreviated as ZnAl–BrO3?–LDHs) as brominating reagents. The para site is much favorable and the ortho site takes the priority if para site is occupied. This reaction featured with excellent regioselectivity, cheap brominating reagents, mild reaction condition, high atom economy, broad substrate scope, and provided an efficient method to synthesize bromophenols.
Phenol compound ortho-position direct fluorination method
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Paragraph 0052-0054, (2020/04/17)
The invention relates to a phenol compound ortho-position direct fluorination method which comprises the following steps: reacting a phenol compound shown in a formula (1A) with a fluorination reagentin a solvent under the action of a photocatalyst and a light source at room temperature, and separating and purifying a reaction mixture after the reaction to obtain a fluorinated phenol compound shown in a formula (2A). The advantages are as follows: the method for directly fluorinating phenol by organic photocatalysis is simple in operation process; raw materials are commercialized and easy toobtain; the photocatalyst is low in price, easy to obtain and environmentally friendly; the reaction condition is mild; the site selectivity is high; the reaction is efficient; and a fluorinated phenol derivative can be prepared only through one step.
